Apparatuses for height adjustment couplings for a trailer hitch are known. References in the related art are directed to forms of height adjustment devices or couplings; however, none of the related art references teaches the adjustment mechanism as proposed by the present invention.
Proper height adjustment to keep a trailer as level as possible is very important to the safe and efficient operation of any trailer by a towing vehicle or other towing unit. A level trailer distributes the weight evenly to all tires of the towing vehicle and trailer, creating a more stable and straighter trailer during towing, improving pulling performance. Tires in the trailer and towing vehicle will heat-up less and wear better, thereby lasting longer, when a trailer that is level distributes the load equally to all such tires. A level trailer distributes the weight of a load evenly between the axles of the trailer. Bent axles, broken axles, broken spindles, and broken leaf springs are often caused from excessive weight on one axle caused by unevenly distributed weight from a trailer that is not level. Trailer and towing vehicle brakes perform much better during towing when their weights are evenly distributed to all tires. A level trailer offers a more uniform load to each set of wheel bearings of the wheels to the trailer, creating a longer wheel bearing life for the trailer. In summary, keeping a trailer level, as in the present invention, enhances the wear, safety, and performance of the tires, the axles, the brakes, the wheel bearings, and pulling performance of the trailer and the towing vehicle.
Related art height adjustment apparatuses for towing trailers have many disadvantages. Such devices are limited by their complexity, often requiring two individuals to operate the apparatuses: one person to hold onto an adjusting sleeve, inner tube or other element of the apparatus and make the necessary height adjustment while a second person loosens and tightens set screws or bolts, resets cotter pins or manipulates other height adjustment, load-bearing support elements to said devices. This procedure frequently must be accomplished while the trailer is in a parked position and not coupled to a towing vehicle or other unit. Other related art devices are additionally limited by their safety concerns as well as complexity, requiring the operator to run a parking leg, jack or similar support to the trailer down with the trailer coupled to the towing vehicle, until most of the trailer weight is on the parking leg. The set bolts or other such height adjustment elements to such a device must then be loosened to raise or lower the trailer to the desired height and position using the trailer parking leg. After the desired height is attained, the set bolts are tightened and the parking leg is raised.
Frequently, these related art devices are located on the trailer rather than the towing vehicle or other unit, adding to the complexity of the height adjustment operation, and requiring more than one operator. The related art devices connected to the towing vehicle or other units are generally large and cumbersome, taking up an inordinate amount of room in said towing vehicles.
The operator must complete these complicated steps in the aforementioned related art apparatuses in proper sequence to avoid bodily injury and equipment damage. Such devices are severely limited, being inconvenient, inefficient, and/or unsafe. If their height adjustment is accomplished improperly, by the operator failing to properly fix the height adjustment element to the device or to position the trailer support prior to setting the height adjustment element, or by making another procedural error in hand-adjusting the device, the support features may fail causing injury to the operators or damage to the equipment. With set screw, bolt or cotter pin types of devices, two sets of such support elements are trusted to carry the entire weight of the trailer, a serious safety concern. Adjusting the related art set screw or other related art height adjustment elements requires too much time, too many wrench or other hand tool manipulations, can be difficult to maneuver, and have potential dangerous consequences as noted above. Most trailers are not adjusted to the correct level as a result of the complicated procedure, resulting in the wear, inefficient and safety problems noted above during towing.
Several related art references are directed to height adjustment mechanisms or couplings to trailer hitches. Each of U.S. Pat. No. 4,664,585 to Ambridge et al., U.S. Pat. No. 5,520,030 to Muldoon, U.S. Pat. No. 5,366,338 to Mortensen, U.S. Pat. No. 5,575,493 to Schwartz et al., U.S. Pat. No. 6,095,748 to Zachovich, and U.S. Patent No. 2004/0195801 to Lara disclose height adjusting mechanisms for a trailer hitch; however, none of the references teach the adjustment mechanism as proposed by the current invention. U.S. Pat. No. 5,520,030 to Muldoon discloses a gooseneck trailer locking device having a parking leg, leveling jack located on a trailer operated by a hand crank. U.S. Pat. No. 5,366,338 to Mortensen discloses a motorcycle towing/lifting device with a motorcycle jack operated by a hand crank gear. U.S. Pat. No. 6,095,748 to Zachovich discloses a vehicle lifting device operated by a camming crank. U.S. Pat. No. 4,664,585 to Ambridge et al. discloses a towing vehicle having a lifting beam.
None of these inventions to Muldoon '030, Mortensen '338, Zachovich '748, Ambridge et al. '585, or Schwartz et al. '493 provides the height adjustment elements of the present invention. The height adjustment element of Mortensen '338 discloses merely a lifting device having a winch strap, and that of Muldoon '030 discloses merely the leveling jack attached to the trailer, Zachovich '748 discloses a camming crank device having a riser pivot, Ambridge et al. '585 discloses two hydraulic rams secured to a lifting beam, and Schwartz et al. '493 discloses a hydraulic cylinder attached to a trailer; all of which references lack, and do not teach, the elements of the height adjustment mechanism of the present invention.
U.S. Patent No. 2004/0195801 to Lara and Mortensen '338 disclose load-bearing pins (Lara '801) or locking pins (Mortensen '338) for adjusting the height adjustment mechanism and bearing the load of a gooseneck hitch (Lara '801) or a towed motorcycle (Mortensen '338), which references do not teach the height adjustment mechanism of the present invention. Such related art requires hand tools to carry out the adjustments. Muldoon '030 and Schwartz et al. '493 require the need for a trailer mounted parking leg or landing gear, generally requiring more than one operator for quick, efficient, accurate, and safe height adjustments. Mortensen '338, Zachovich '748, and Ambridge et al. '585 all are complex and cumbersome in their operation, as towing devices, requiring a substantial amount of space and/or power from the towing unit. None of the devices to Muldoon '030, Mortensen '338, Zachovich '748, Ambridge et al. '585, Schwartz et al. '493 or Lara '801 operates in the manner of the present invention, and none of the references to those devices disclose the advantage of the internal screw gear height adjustment mechanism of the present invention. All of the aforementioned related art inventions suffer from one or more of the following disadvantages, set forth above: requiring more than one operator by being located on the trailer, being overly complex in its operation or cumbersome in its size, or by using load-bearing pins or screws or bolts.